"It's like stubbing your toe when you're going 35 mph or more," Gallagher said. "You've got a lot of weight, and a lot of speed combined."

Belote's horse, Atenothnbutdscootr, which had been in the lead position on the outside, went down, and Belote was unseated.

Gallagher said Belote was then hit by Warrington's horse, and then by Givens' rig, which he said "apparently had considerable impact" with Belote.

"Mr. Belote received a great deal of medical attention on the track, as did the two other drivers," Gallagher said.

Belote died en route to Milford Memorial Hospital, where Givens was taken for treatment of injuries that included a broken leg, Gallagher said. Warrington, who survived a bad accident in California a few years ago, was taken by helicopter to Christiana Hospital in Newark.

None of the horses was put down.

"This was an unavoidable accident," said Gallagher, who could not recall any other fatality in Delaware harness racing. "A second before it happened, you would have looked at that thing and marveled about how straight they were racing."

Belote won 1,986 races in his career, amassing nearly $11 million in purse money, and worked as a trainer as well as a driver.

NOTES: The Preakness field expanded to seven horses Monday when trainer Steve Klesaris entered Diabolical, who finished second to Barbaro in the Laurel Futurity in November. Three other horses -- Greeley's Legacy, Platinum Couple and Ah Day -- also might enter the field for Saturday's middle jewel of the Triple Crown at Pimlico in Baltimore. ... Scottsbluff, a 4-year-old gelding, set a world record Monday, running 5 1/2 furlongs on the turf course in 1:00.26 in winning the $70,800 Bullet Stakes at Hollywood Park in Inglewood, Calif. Scottsbluff, making his first turf start, carried 120 pounds -- the same weight carried by Pembroke when he established the old world record of 1:00.46 at Hollywood Park in 1995.